Rinnai RU80 Water Heaters Review

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Rinnai RU80 tankless water heaters with the second largest
capacity of all Rinnai that utilize the condensing technology
for the ultra efficient water heating. See the review of the top
features and compare specs between the indoor and outdoor models.

Models review

Rinnai RU80 water heaters are designed as
the indoor
RU80i and outdoor RU80e type both models utilize two exchangers; one
that
pre-heats the incoming water by using the temperature of the flue
gases, and the other that heats water inside the main, made of copper
exchanger. As other Rinnai tankless heaters, RU80 also uses a
modulating burner
or gas
valve,
which allows power adjustments from its minimum to the
maximum value, depending upon the water flow. Due to the condensing
technology, the energy
efficiency is much higher than in non-condensing type. They
are
mainly used in homes with up to three bathrooms.

The
warranty on either RU80 is 12
years on the heat exchanger when used in residential applications, or 10
years if used in potable water and space heating.

Rinnai RU80i

Rinnai
RU80i are
indoor direct
vent water heaters that are designed to use either a two pipe system;
one pipe for the air and one for flue gases, or coaxial type (a pipe
inside the pipe). Its design allows a flexible installation due to the
long
vent pipe, while the layout can be vertical or horizontal.

These
units come with the built-in MC-91-2US type controller while the
MCC-91-2US is optional and is used in commercial and hydronic
applications. The controller MCC-91-2US allows
heating water up to the
temperature of 185 F.

How to Buy

The price range for Rinnai RU80IN, as the natural gas
model, and the RU80IP, as the propane model, is
from $1100 to $1300 found on Amazon.com, both models having an average
4-5 star reviews.

Rinnai RU80e

Rinnai
RU80e doesn't
require pipes for the air intake or
exhaust as
they are already installed outside. The digital temperature controller
is not a built-in, but it is provided with the unit.

How to Buy

The price range for the Rinnai RU80EN, as the natural gas
and outdoor model, and the Rinnai RU80EP, as the propane
model, is from $1000 to $1300 found on Amazon.com, both models having
an average 4-5 star reviews.

Features review

• Automatic ignition when all the conditions are
  met.

• Environment friendly and Ultra Low NOx burner that
  complies with the 20 ppm
  NOx emission
  levels.

• Digital temperature controller MC-91-2US is used
  to monitor the temperature, adjust the settings and display the error
  codes.

• Improved detection of the lime-scale in the heat
  exchanger.

• Built-in Rinnai Circ-Logic
  recirculation program that cycles an external pump for better comfort
  and higher efficiency.

• Temperature lock feature that prevents accidental or
  unauthorized
  temperature changes.

• Water flow sensor, electronic water control device and
  electronic by-pass control.

• Safety features such as the flame and boiling
  protection, combustion fan check, remaining
  flame OHS, automatic frost protection (protects the unit when the
  outside temperature is up to -22 F).

• Diagnostic systems helps in service.

• Electric PC board.

Specifications - Technical Data

Models --- Specifications	RU80i	RU80e
Gas Input (BTUs)	15,200 - 152,000	15,200 - 152,000
Water Flow (GPM)	0.26-8.0	0.26-8.0
Energy Factor EF	0.96	0.96
Activation rate (GPM)	0.4	0.4
Temp. settings (F)	98-140	98-140
Electric consumption (Watts)	42	41
Max. vent length (ft)	41' - one pipe system 42' - two pipe system	N/A
Altitude height (ft)	10200	10200
Size (inch)	18.3x26x10	18.3x26x10
Weight (lbs)	70.5	70.5

(Photo credit to Rinnai)